Bathory’s singular vision of metal as a demonic night ritual of sick and aberrant riff-cycles reaches fever-pitch on Under The Sign Of The Black Mark, but the formula is also infected by an increased awareness of rock sensibility – mainman Quorthon spits and curses behind a shield-wall of infernal electric noise and unleashes maniacal guitar solos, while offering occasional glimpses of song structure. Bathory next turned to a new model inspired by Viking lore, leaving Under The Sign Of The Black Mark as an aural codex informing all black Satanic metal to come.